Sensitivity of a rapid immuno-chromatographic test for hepatitis C antibodies detection.

BACKGROUND AND OBJECTIVES: Enzyme-linked immunoassays (ELISA) are the most widely used anti-hepatitis C virus (HCV) screening tests but simple, instrument and electricity-free screening tests have been developed with results available in a few minutes. METHODS: The sensitivity of a rapid immuno-chromatographic assay for the detection of anti-HCV antibodies was evaluated on 421 HCV RNA-positive samples from chronic carriers and compared with ELISA method. RESULTS: The sensitivity of the ELISA method was 99.3% and the sensitivity of the rapid test was 95.5%. False negative results were independent of HCV genotype, but were associated with human immunodeficiency virus (HIV)-positive status. Among HIV-negative people, sensitivities of the rapid test and the EIA assay were 99.2% and 100%, respectively. Whereas among HIV-positive people, sensitivities were 77.5% and 96.3%. CONCLUSIONS: The immuno-chromatographic test is rapid and simple, and could be used along with rapid anti-HIV determination, in settings with limited facilities or when rapid results are required.

Comparison of real-time RT-PCR assays for hepatitis E virus RNA detection.

BACKGROUND: Hepatitis E virus (HEV) is an increasing cause of acute viral hepatitis in developed countries. Serological testing alone may fail to diagnose acute infection, especially in immunocompromised patients, which justifies the use of molecular assays for diagnosis. Few studies have compared accuracy of HEV RNA detection assays. OBJECTIVES: The performances of five real-time PCR procedures for HEV RNA detection were compared. STUDY DESIGN: First, RNA quantification of hepatitis E diluted standards of 3a and 3b genotypes were performed. Secondly, forty-seven clinical samples of patients with known acute HEV infection were tested using five hepatitis E RNA detection methods of assigned letters A, B, C, D and E. RESULTS: Standards of HEV 3a genotype were detected in 100% of replicates with 2500 UI/ml of sensitivity by using A, B and C assays. Standards of HEV 3b genotype were more accurately detected with a sensitivity of 25 UI/ml in 100% of replicates using C assay and were detected in 100% of replicates with 2500 UI/ml of sensitivity by using A, B and E assays. Overall, B assay detected all of 250 UI/ml dilution and occasionally the 25 UI/ml dilution on both subtypes. The detection rates of clinical samples were 100%, 100% 97%, 97% and 83% for the respective A, B, C, D and E assay. Assays A and B were well correlated, independently of the subtype. However, discrepancies were observed when these techniques were compared to C, D and E assays according to the different subtypes. CONCLUSION: A and B assays appear reliable for HEV RNA detection. These assays target the ORF2/3 overlapping region, described as more conserved than ORF2.